I am using google keyword tool to search keywords for my website , I wish if you can tell me what are the best alternatives that will get me more useful results .
Sorry but in my opinion nothing beats Google's tool if what you are trying to do is rank on Google. there are tools out there like Market Samurai which take data from Google, and try to come up with their own fancy formulas. But in the end, it's all based on the data available for free right from Google. If I were you, I'd learn more about how to use that tool as it really provides everything you need at no charge.
I like Ubersuggest.org because it is a g00gle suggest scrapper and will give you lots of actually searched terms and long tail keywords.
I think Google adword is the best keyword tool . No other keyword tool beats this . I use this tool from last 2 years and it gives always good results . If Google’s best keyword tool is there then you are asking for another one ?
I agree with @afoley77, Google Adwords is one of the best keyword research tools. with this tool you can make your keyword research process more accurate and effective.
If you're trying to rank on Google, you might as well use the data that they're providing you to do so.
I use seomoz and Long tail pro for my Keyword research. It's true that they retrieve data from Google Keyword Tool but they tend to refine it well to only what you need.
I use Traffic Travis for my Keyword Research, aside from the Google Keyword Tool. You can also try Wordtracker. Hope that helps. Have a good day!
Listen to everyone here and use them all for sure! Use ubersuggest and google search suggest and amazon search suggest to get ideas, then use traffic travis and wordtracker and google keyword tool to get the stats for all those words you just found! Then type the word you like into google and make sure the first page competition is not chock full of huge authority sites, (which would make it impossible for you to rank). Authority sites meaning the whole first page is covered by sites as well known and reputable as wikipedia. Hope that helps, let me know if you need more ideas! Matt